Dotenv is supported by the community.
Special thanks to:
Dotenv is a zero-dependency module that loads environment variables from a .env file into process.env. Storing configuration in the environment separate from code is based on The Twelve-Factor App methodology.
# install locally (recommended)
npm install dotenv --saveOr installing with yarn? yarn add dotenv
Create a .env file in the root of your project:
S3_BUCKET="YOURS3BUCKET"
SECRET_KEY="YOURSECRETKEYGOESHERE"As early as possible in your application, import and configure dotenv:
require('dotenv').config()
console.log(process.env) // remove this after you've confirmed it is working.. or using ES6?
import * as dotenv from 'dotenv' // see https://github.com/motdotla/dotenv#how-do-i-use-dotenv-with-import
dotenv.config()
import express from 'express'That's it. process.env now has the keys and values you defined in your .env file:
require('dotenv').config()
...
s3.getBucketCors({Bucket: process.env.S3_BUCKET}, function(err, data) {})If you need multiline variables, for example private keys, those are now supported (>= v15.0.0) with line breaks:
PRIVATE_KEY="-----BEGIN RSA PRIVATE KEY-----
...
Kh9NV...
...
-----END RSA PRIVATE KEY-----"Alternatively, you can double quote strings and use the \n character:
PRIVATE_KEY="-----BEGIN RSA PRIVATE KEY-----\nKh9NV...\n-----END RSA PRIVATE KEY-----\n"Comments may be added to your file on their own line or inline:
# This is a comment
SECRET_KEY=YOURSECRETKEYGOESHERE # comment
SECRET_HASH="something-with-a-#-hash"Comments begin where a # exists, so if your value contains a # please wrap it in quotes. This is a breaking change from >= v15.0.0 and on.
The engine which parses the contents of your file containing environment variables is available to use. It accepts a String or Buffer and will return an Object with the parsed keys and values.
const dotenv = require('dotenv')
const buf = Buffer.from('BASIC=basic')
const config = dotenv.parse(buf) // will return an object
console.log(typeof config, config) // object { BASIC : 'basic' }You can use the --require (-r) command line option to preload dotenv. By doing this, you do not need to require and load dotenv in your application code.
$ node -r dotenv/config your_script.jsThe configuration options below are supported as command line arguments in the format dotenv_config_<option>=value
$ node -r dotenv/config your_script.js dotenv_config_path=/custom/path/to/.env dotenv_config_debug=trueAdditionally, you can use environment variables to set configuration options. Command line arguments will precede these.
$ DOTENV_CONFIG_<OPTION>=value node -r dotenv/config your_script.js$ DOTENV_CONFIG_ENCODING=latin1 DOTENV_CONFIG_DEBUG=true node -r dotenv/config your_script.js dotenv_config_path=/custom/path/to/.envYou need to add the value of another variable in one of your variables? Use dotenv-expand.
You need to keep .env files in sync between machines, environments, or team members? Use dotenv-vault.
See examples of using dotenv with various frameworks, languages, and configurations.
- nodejs
- nodejs (debug on)
- nodejs (override on)
- esm
- esm (preload)
- typescript
- typescript parse
- typescript config
- webpack
- webpack (plugin)
- react
- react (typescript)
- express
- nestjs
- fastify
Dotenv exposes two functions:
configparse
config will read your .env file, parse the contents, assign it to
process.env,
and return an Object with a parsed key containing the loaded content or an error key if it failed.
const result = dotenv.config()
if (result.error) {
throw result.error
}
console.log(result.parsed)You can additionally, pass options to config.
Default: path.resolve(process.cwd(), '.env')
Specify a custom path if your file containing environment variables is located elsewhere.
require('dotenv').config({ path: '/custom/path/to/.env' })Default: utf8
Specify the encoding of your file containing environment variables.
require('dotenv').config({ encoding: 'latin1' })Default: false
Turn on logging to help debug why certain keys or values are not being set as you expect.
require('dotenv').config({ debug: process.env.DEBUG })Default: false
Override any environment variables that have already been set on your machine with values from your .env file.
require('dotenv').config({ override: true })The engine which parses the contents of your file containing environment variables is available to use. It accepts a String or Buffer and will return an Object with the parsed keys and values.
const dotenv = require('dotenv')
const buf = Buffer.from('BASIC=basic')
const config = dotenv.parse(buf) // will return an object
console.log(typeof config, config) // object { BASIC : 'basic' }Default: false
Turn on logging to help debug why certain keys or values are not being set as you expect.
const dotenv = require('dotenv')
const buf = Buffer.from('hello world')
const opt = { debug: true }
const config = dotenv.parse(buf, opt)
// expect a debug message because the buffer is not in KEY=VAL formMost likely your .env file is not in the correct place. See this stack overflow.
Turn on debug mode and try again..
require('dotenv').config({ debug: true })You will receive a helpful error outputted to your console.
No. We strongly recommend against committing your .env file to version
control. It should only include environment-specific values such as database
passwords or API keys. Your production database should have a different
password than your development database.
No. We strongly recommend against having a "main" .env file and an "environment" .env file like .env.test. Your config should vary between deploys, and you should not be sharing values between environments.
In a twelve-factor app, env vars are granular controls, each fully orthogonal to other env vars. They are never grouped together as “environments”, but instead are independently managed for each deploy. This is a model that scales up smoothly as the app naturally expands into more deploys over its lifetime.
The parsing engine currently supports the following rules:
BASIC=basicbecomes{BASIC: 'basic'}- empty lines are skipped
- lines beginning with
#are treated as comments #marks the beginning of a comment (unless when the value is wrapped in quotes)- empty values become empty strings (
EMPTY=becomes{EMPTY: ''}) - inner quotes are maintained (think JSON) (
JSON={"foo": "bar"}becomes{JSON:"{\"foo\": \"bar\"}") - whitespace is removed from both ends of unquoted values (see more on
trim) (FOO= some valuebecomes{FOO: 'some value'}) - single and double quoted values are escaped (
SINGLE_QUOTE='quoted'becomes{SINGLE_QUOTE: "quoted"}) - single and double quoted values maintain whitespace from both ends (
FOO=" some value "becomes{FOO: ' some value '}) - double quoted values expand new lines (
MULTILINE="new\nline"becomes
{MULTILINE: 'new
line'}
- backticks are supported (
BACKTICK_KEY=`This has 'single' and "double" quotes inside of it.`)
By default, we will never modify any environment variables that have already been set. In particular, if there is a variable in your .env file which collides with one that already exists in your environment, then that variable will be skipped.
If instead, you want to override process.env use the override option.
require('dotenv').config({ override: true })Your React code is run in Webpack, where the fs module or even the process global itself are not accessible out-of-the-box. process.env can only be injected through Webpack configuration.
If you are using react-scripts, which is distributed through create-react-app, it has dotenv built in but with a quirk. Preface your environment variables with REACT_APP_. See this stack overflow for more details.
If you are using other frameworks (e.g. Next.js, Gatsby...), you need to consult their documentation for how to inject environment variables into the client.
Yes! dotenv.config() returns an object representing the parsed .env file. This gives you everything you need to continue setting values on process.env. For example:
const dotenv = require('dotenv')
const variableExpansion = require('dotenv-expand')
const myEnv = dotenv.config()
variableExpansion(myEnv)Simply..
// index.mjs (ESM)
import * as dotenv from 'dotenv' // see https://github.com/motdotla/dotenv#how-do-i-use-dotenv-with-import
dotenv.config()
import express from 'express'A little background..
When you run a module containing an
importdeclaration, the modules it imports are loaded first, then each module body is executed in a depth-first traversal of the dependency graph, avoiding cycles by skipping anything already executed.
What does this mean in plain language? It means you would think the following would work but it won't.
// errorReporter.mjs
import { Client } from 'best-error-reporting-service'
export default new Client(process.env.API_KEY)
// index.mjs
import dotenv from 'dotenv'
dotenv.config()
import errorReporter from './errorReporter.mjs'
errorReporter.report(new Error('documented example'))process.env.API_KEY will be blank.
Instead the above code should be written as..
// errorReporter.mjs
import { Client } from 'best-error-reporting-service'
export default new Client(process.env.API_KEY)
// index.mjs
import * as dotenv from 'dotenv'
dotenv.config()
import errorReporter from './errorReporter.mjs'
errorReporter.report(new Error('documented example'))Does that make sense? It's a bit unintuitive, but it is how importing of ES6 modules work. Here is a working example of this pitfall.
There are two alternatives to this approach:
- Preload dotenv:
node --require dotenv/config index.js(Note: you do not need toimportdotenv with this approach) - Create a separate file that will execute
configfirst as outlined in this comment on #133
Try dotenv-expand
Use dotenv-vault
See CONTRIBUTING.md
See CHANGELOG.md
These npm modules depend on it.
Projects that expand it often use the keyword "dotenv" on npm.